The invention concerns a dental handtool with an extended handtool sleeve, in the center of which a driving shaft is located for the rotary movement of a tool for dental treatment. The tool is fitted at one end of the sleeve, and at the opposite end of the sleeve to which the tool is fitted, a driving part can be fitted to the handtool. The driving part is essentially free to rotate, and between the driving part and the handtool a separable coolant pipe is provided to feed coolant to the area of the dental treatment tool.
Such handtools, heretofore, are known from a leaflet of the applicant's product literature PR-Nr. 7230/4-III.71, page 3 and 4. Here the driving part is provided with a discharge pipe piece and with an inlet pipe piece on the handtool for a flexible coolant pipe. Should one now wish to place a different handtool onto the driving part, the coolant pipe must first be freed from the previously used handtool, and after connecting the new handtool, the coolant pipe must again be pushed onto the inlet pipe stub. In addition, even with an excessive length of flexible coolant pipe, free rotation of the handtool against the driving part of more than 360.degree. is not possible, because the coolant pipe winding itself around the handtool or the driving part by the rotation, blocks further turning by a rotational path depending on the length of the coolant pipe.
Accordingly, an object of the present invention is to produce a dental handtool of the foregoing character, in which an essential, required free rotation between the handtool and the driving part is obtained and special hand operations are avoided when connecting or disconnecting, the coolant pipe sections in the driving part and in the handtool.